James T. Cronin and Joseph Travis. 1986. Size-limited predation on larval Rana areolata (Anura: Ranidae) by two species of backswimmer (Insecta: Hemiptera: Notonectidae). Herpetologica 42: 171-174.
ABSTRACT: Size-limited insect predators can act as agents of selection for tadpole growth rate and body size. We designed an experiment to test for size-limited predation on larval Rana areolata by adults of two species of notonectid insects. An individual insect, either Notonecta indica or N. undulata, was exposed to 21 tadpoles from one of four tadpole size classes. Predation rate of N. undulata decreased continuously with increasing tadpole size. By contrast, Notonecta indica did not attack newly hatched tadpoles but consumed considerable numbers of tadpoles in the second size class. The subsequent rate of N. indica predation was a decreasing function of increasing tadpole size. These daily rates of predation were comparable to those displayed by other insect predators of tadpoles, although the size range of tadpoles attacked is narrower for notonectids than for other insect predators.
